Open mold multi-lap manufacturing process

ABSTRACT

A multi-lap mold manufacturing system includes an overhead rail circuit upon which a multiple of molds transit a closed loop for a multiple of laps. The system is separated into Zones in which a particular mold operation is performed relative to which lap each of the plurality of molds has completed. At least one of the Zones is a spray Zone in which the mold is sprayed robotically. Robot utilization is extremely high as multiple spray operations occur in but a few spray Zones. Application of exceedingly expensive environmental emission control devices is at least partially mitigated by the reduced number of spray stations and the much smaller factory footprint. Consolidation of multiple spray operations into a few spray Zones also advantageously simplifies the control of chemical and ambient variables which improves production efficiencies and reduces operator dependency.

BACKGROUND OF THE INVENTION

The present invention relates to an open mold manufacturing process, andmore particularly to a manufacturing system in which molds make multiplelaps around the same circuit during which predetermined operations areperformed for each lap.

Open mold fiberglass reinforced plastic molding systems are well known.Molds travel once along an assembly line. A plurality of operations areperformed at stations along the assembly line until a finished part isremoved from the mold at the end of the assembly line.

Multiple stations along the assembly line are spray stations. As themolds transit the spray station a particular spraying operation isperformed. Such spray operations include gelcoat andresin/catalyst/chopped fiberglass fixture application. Multiple coatsare often required for one or more spraying operations necessitatingadditional spray stations. Stringent environmental regulations apply tothese spraying operations as the sprayed material involves severalchemical reactions. Conventional spray stations provide an openenvironment in which an airflow is directed from behind a spray operatorto direct mold overspray into an exhaust port.

Environmental regulations are becoming more and more inflexible. Theexpense of providing environmental emission control devices which meetenvironmental regulations often results in cost prohibitivemanufacturing facilities. Often older facilities become non-compliantand must be idled. The expense of the regulation may be particularlyhigh for an assembly line type molding system as spraying occurs atmultiple locations along the assembly line. The entire facility istherefore typically subjected to particularly harsh environmentalregulations.

Assembly line type molding systems require a rather large manufacturingfacility footprint as a curing station typically follows each sprayingstation. The sequential nature of the assembly line environment providesfor constant movement of the molds. The curing stations must be of alength to assure proper curing of the prior spray operation. Multiplelengthy curing stations greatly lengthens the assembly line. A largermanufacturing facility is subject to harsher environmental regulationsthan a smaller facility.

The sequential nature of the assembly line environment provides multiplespray stations spaced along its length. Each spray station is vulnerableto many exogenous variables that are difficult to control in a costeffective manner. Control of these variables is only magnified in largermanufacturing facilities.

Typically, human operators at each spray station are highly trained tominimize volatility in the manufacturing process. Many individualoperators, even though highly trained, still may create manufacturingprocess volatilities due to variance in human technique and processmanipulation. Robotic sprayers are often provided in place of operatorsto increase spraying consistency. However, this may simply result inmany robotic spray stations replacing many human spray stations withouta substantial reduction in expense.

Accordingly, it is desirable to provide an open mold manufacturingprocess which meets stringent environmental regulations within a smallfootprint facility. It is further desirable to minimize manufacturingprocess volatilities due to exogenous and human variables in a costeffective manner.

SUMMARY OF THE INVENTION

The multi-lap mold manufacturing system according to the presentinvention is utilized for open molding of large parts, and in particularbath tubs and shower surrounds. The system includes an overhead railcircuit upon which a multiple of molds transit a closed loop. The moldshang from the rail system such that access is readily provided to theentire mold outer surface. The system is separated into Zones in which aparticular mold operation is performed relative to which lap each of theplurality of molds has completed.

At least one of the Zones is a spray Zone with a spray robot which movesalong and traverses a rail mount such that a single robot accessesmultiple spray Zones. Spray operations are concentrated in these sprayZones. Robot utilization is extremely high as multiple spray operationsoccur in but a few spray Zones. Stringent environmental regulations areapplicable to facilities including these Zones. Application ofexceedingly expensive environmental emission control devices istherefore at least partially mitigated by the reduced number of spraystations and the much smaller factory footprint. Consolidation ofmultiple spray operations into a few spray Zones also advantageouslysimplifies the control of chemical and ambient variables which improvesproduction efficiencies. In addition, the consolidation of sprayoperations minimizes the requirement for more highly skilled labor tothe spray Zones and minimizes the requirement for robot usage.

The multiple of Zones include Zones in which other spray operations andrelative uncomplicated manual tasks are performed. The Zones furtherinclude curing Zones which are primarily queues in which the previousspray operations are cured. These curing and other spray Zones requirethe entire facility to be defined under environmental regulations.However, as the present invention provides a facility having a smallerfootprint, expenses are accordingly reduced.

The molds are segregated into two parallel queues depending upon whichlap the particular mold has completed. The molds are released from thequeues such that the molds are staged in a third queue in a reoccurringsequence. The molds then leave the third queue to begin another laparound the system until a finished part is produced after apredetermined number of laps are completed.

Three parts come out of the spray Zones every three minutes. Onefinished part is pulled from the mold every three minutes when thirtymolds are traversing the system. Total cycle time is approximatelyninety minutes per molded part using known chemistry.

The present invention therefore provides an open mold manufacturingprocess which meets stringent environmental regulations within a smallfootprint facility. The present invention also minimizes manufacturingprocess volatilities due to exogenous and human variables in a costeffective manner.

BRIEF DESCRIPTION OF THE DRAWINGS

The various features and advantages of this invention will becomeapparent to those skilled in the art from the following detaileddescription of the currently preferred embodiment. The drawings thataccompany the detailed description can be briefly described as follows:

FIG. 1 is a general floor plan view a multi-lap mold manufacturingsystem designed according to the present invention;

FIG. 2 is a chart diagramming spray operations relative to lap and Zone;

FIG. 3 is a block diagram schematically illustrating the multi-lap moldmanufacturing system of FIG. 1;

FIG. 4A is the block diagram of FIG. 3 illustrating a set of molds in afirst three positions;

FIG. 4B is the block diagram of FIG. 3 illustrating the set of molds ina second three positions; and

FIG. 4C is the block diagram of FIG. 3 illustrating the set of molds ina third three positions.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 illustrates a factory layout for a multi-lap mold manufacturingsystem 20. System 20 is preferably utilized for open molding of largeparts, and in particular bath tubs and shower surrounds. The system 20includes an overhead rail circuit 22 upon which a multiple of molds 24transit a closed loop. The molds 24 hang from the rail system such thataccess is readily provided to the entire mold outer surface. It shouldbe understood that other transit systems such as tracks, guided vehiclesand the like will also benefit from the present invention.

The system 20 is separated into Zones in which a particular moldoperation is performed depending upon which lap the mold 24 is presentlyon (also illustrated by the circuit map of FIG. 3 and the lap matrix ofFIG. 2). The mold lap is designated by letters A-C, in which letter Adesignates that the mold is on the first lap; letter B designates thatthe mold is on the second lap; and letter C designates the mold is onits third and final lap. Preferably, the molds 24 travel through thesystem 20 in sets of three and in the order CAB. It should be understoodthat although three laps and sets of three molds 24 are discussed in thedescribed embodiment, any number of laps and mold sets will benefit fromthe present invention.

The circuit alternatively or additionally provides one or more exitspurs 22 r 1, 22 r 2 which may be utilized to unload, offload, repair,replace, modify and/or otherwise add or remove molds 24 from the circuit22. Preferably, a minor repair exit spur 22 r 1 from the circuit 22provides for minor mold repair of a mold 24 d essentially on-line. Formajor repairs, a transportation device such as a dolly, forklift, orother transportation may be moved adjacent the exit spur 22 r 2 toremove the mold 24D to a location remote from the circuit 22. Likewise,the molds 24 may also be removed and returned to a mold storage area Ssuch that various batches of molds can be specifically provided in realtime to meet particular customer orders by retrieving particular lessutilized molds from the mold storage areas S.

Referring to FIGS. 2 and 3, the system 20 is schematically illustratedas separated in Zones by operation. Zone 1 is a spray Zone in which themold 24 is sprayed with a layer of resin referred herein as “gelcoat”.The gelcoat, as generally known, is a hardenable resin that becomes thevisible surface of the finished product. Zone 1 is a spray booth stationin which a spray robot (illustrated schematically at 25A in FIG. 1)moves along and traverses relative a rail mount 26. Zone 2 is also aspray Zone which is separated into a first spray Zone 2 a and a secondspray Zone 2 b. Zone 2 b is a spray Zone in which the mold 24 is sprayedwith a first layer of resin/catalyst/chopped fiberglass mixture referredherein as “first chop”. Zone 2 a is a spray Zone in which the mold 24 issprayed with a second layer of the resin/catalyst/chopped fiberglassmixture referred herein as “cover”. A second spray robot 25B is alsolocated within Zone 2 and preferably moves along rail mount 26. Thesecond robot 25B preferably traverses between Zone 2 a and Zone 2 b suchthat robot 25B utilization is one hundred 100 percent. That is, robot25B is never idle when the molding system 20 is operational as it isalternatively spraying the same mixture into Zones 2 a and 2 b.

Concentrated spraying only occurs in Zones 1, 2 a, and 2 b. The highconcentration of spraying and the associated low airflow requirementsprovides for more effective utilization of expensive environmentalemission control devices. Moreover, as the same spray Zones 1, 2 a, and2 b are used repeatedly on each lap, a large number of spray operationsis replaced by a small number of spray Zones. That is, a large number ofspray operations (higher airflow lower spraying concentration) along aconventional assembly line type molding system are replaced by sprayZones 1, 2 a and 2 b which are utilized on each mold lap. Application ofexceedingly expensive environmental emission control devices istherefore at least partially mitigated by the reduced number ofconcentrated spray stations, the associated low airflow requirements toeffectively remove the emissions and the much smaller factory footprint.Preferably, the present invention utilizes one exhaust port at Zone 1, asecond exhaust port for Zones 2 a, and 2 b, and a third and/oradditional exhaust port for the remainder of the facility. It should beunderstood that although three exhaust ports are discussed in thedescribed embodiment, any number of ports will benefit from the presentinvention. The present invention, however, provides a reduction ofexhaust ports which receive a higher concentration of chemicals thanheretofore conventional molding facilities.

Consolidation of multiple spray operations into a few spray Zones alsoadvantageously simplifies the control of chemical and ambient variableswhich improves production efficiencies. It should be understood thatalthough robots are preferred for Zones 1, 2 a, and 2 b, operators inproper protective equipment may additionally or alternatively be locatedin the spray Zones. In addition, the consolidation of spray operationsminimizes the requirement for more highly skilled labor to the sprayZones or the required number of robots.

Zones 4-10 are mold operations which require minimal orlow-concentration spraying and relatively uncomplicated manual tasks.Zone 7, for instance, is not utilized on each lap. As described above,at least one common exhaust port is typically adequate for these Zones.Zones 7-10 require minimum mold 24 stops. Zone 7 provides for arelatively light barrier coat spray and foam coat spray operation incombination with mold manipulation to provide for effectivegravity-assisted spraying operations. The Zone 7 spray operations, incontrast to those in Zones 1, 2 a, and 2 b, occur within a spray boothhaving one of the system-wide exhaust ports.

Zone 8 is where a completed part is removed or “pulled” from the mold24, i.e., demolded after it has passed through lap C. Zones 8-10 a iswhere the bare mold is wiped down and cleaned after demolding.

Zone 10 a provides for continued wiping while Zones 10 b and 10 c(FIG. 1) also operate as a staging area for molds 24 which are waitingto move into the spray Zones 1, 2 a, and 2 b. The molds 24 are alsoseparated by lap in Zone 10. Molds which are on lap A and C are stagedalong rail 22 a (FIG. 1) for Zone 1 and 2 a while molds on lap B arestaged along rail leg 22 b (FIG. 1) for Zone 2 b. Preferably, moldstravel to Zones 1 and 2 in a down minute of the robot so full time isavailable for spraying.

Zones 4 a, 4 b, 5 a, 5 b and 6 are primarily queues in which theprevious spray operations are cured. The system 20 footprint is furtherreduced as the curing Zones 4 a, 4 b, 5 a, 5 b and 6 are integratedwithin the rail circuit 22, i.e., a separate curing area is notsequentially located after each spraying operation along an assemblyline.

Zones 4 a/5 a queue the molds on laps A and B in a BABABABA arrangementwhile Zones 4 b/5 b queue only the molds on lap C (FIG. 1). Notably,between Zone 2 and Zone 4 is an arbitrary line which is designated Zone3 where a lap is completed and the lap designation is increased by oneas will be further described. Two molds 24 leave Zones 4 a/5 a onlyafter one mold leaves Zones 4 b/5 b such that molds within Zone 6 arealways sequenced in sets of three in a CAB order (FIG. 1).

With reference to FIGS. 4A-4C, movement of one set S of three molds(each on a different lap) will be described to illustrate operation ofthe system 20. As mentioned, the molds 24 are staged in Zone 6 in theCABCABCAB order. Molds 24 within Zones 4 a, 4 b, 5 a, 5 b move from leftto right in FIGS. 4A-4C which molds within Zone 6 move from right toleft.

Referring to FIG. 4A, there are three positions for the system 20. Eachposition represents the same amount of time which, preferably, isapproximately one minute. The three positions continue to rotate throughpositions: POSITION ONE, POSITION TWO, POSITION THREE; POSITION ONE,POSITION TWO, POSITION THREE; etc. That is, the molds are alwaysrotating through the system 20. It should also be understood that moldset S has been selected for descriptive reasons and the set S may havebeen described with referenced to any beginning position.

It should be further understood that start-up and shut-down of thesystem 20 occurs in a staged manner. That is, only ⅓ of the molds areprocessed during the A lap alone. A second ⅓ of the molds beginprocessing on the A lap—now the original ⅓ are on the B lap. Finally,the last ⅓ begin processing on the A lap—now the original ⅓ are on the Clap; and the second ⅓ are on the B lap. Labor may therefore be added andremoved from the system 20 in a staged manner to further decreaseexpense.

Beginning with a mold set S (illustrated within phantom line) inPOSITION ONE, the first mold 24 of the set S is on lap C and is withinZone 7 (FIG. 3) while the following two molds 24 are on lap A and lap Bwithin Zone 6. The mold 24 which is depicted as on lap A actuallyretains a completed product. In other words, the mold, althoughdesignated as being on lap A, actually contains a finished part whichhas cured in Zone 5/6.

At POSITION ONE, the lap C mold undergoes a foam spray operation (FIG.2) for one minute within Zone 7. Schematically, the box is hatched asthe mold is undergoing the first minute of the task. Also identifiedschematically, the lap designator C is in the top of the box to indicatethat the mold spends the first minute in Zone 7.

At POSITION TWO, the C mold has moved to Zone 9, the A mold has movedinto Zone 8, and the B mold has moved to Zone 7. The C mold is simplypassing through Zone 9 as no operation is performed (FIG. 2). Asdescribed above, the A mold has the finished part removed such that themold 24 is set to start the entire process again. Schematically, theZone 8 box is hatched as the mold is undergoing the first minute of thetask. The B mold has moved into Zone 7. The B mold undergoes the firstminute of manipulation and barrier coat spray (FIG. 2). Schematically,the Zone 7 box is hatched as the mold is undergoing the first minute ofthe task.

At POSITION THREE, the C mold, A mold, and the B mold remain in the sameZones. As the C mold, A mold, and the B mold remain in the same Zone asPOSITION TWO, the lap designators schematically move to the centralportion of their respective box to indicate that the molds are spendingtheir second minute in the same Zone. The C mold still has no operationperformed (FIG. 2). The A mold is now wiped down in the second minute atZone 8, however this is the first minute of the wipe operation.Schematically, the Zone 8 box is hatched as the mold is undergoing thefirst minute of the wipe operation. The B mold remains in Zone 7 whilethe second minute of the two minute long task (FIG. 2) is completed.Schematically, the Zone 8 box is shaded as the mold is undergoing thesecond minute of the barrier coat operation (FIG. 2).

Referring to FIG. 4B POSITION ONE, the C mold has moved to Zone 10 b,the A mold has moved into Zone 10 a, and the B mold has moved to Zone 9.As the C mold, A mold, and the B mold move to new Zones, the lapdesignators schematically move to the top portion of their respectivebox to indicate that the molds are spending their first minute in theirrespective Zones. Schematically, the Zone 10 a box is shaded as the Amold is undergoing the second minute of the wipe operation (FIG. 2). Themolds are being staged in Zone 10 (FIG. 1) prior to entering the sprayZones.

At POSITION TWO, the C mold has moved to Zone 2 a, the A mold has movedinto Zone 1, and the B mold has moved to Zone 10 c. No operations areperformed. As the C, A and B mold move to new Zones, the lap designatorsschematically move to the top portion of their respective box toindicate that the molds are spending their first minute in theirrespective Zones. It should be noted, however, that when the molds reachstaging Zone 10, the A mold and C mold are staged along rail 22 a(FIG. 1) for Zones 1 and 2 a, respectively, while the B mold is stagedalong rail leg 22 b (FIG. 1) for Zone 2 b.

At POSITION THREE, the C mold and the A mold remain in the same Zones.As the C mold and A mold remain in the same Zone as POSITION TWO, thelap designators schematically move to the central portion of theirrespective box to indicate that the molds are spending their secondminute in the same Zone. The B mold moves into Zone 2 b and the lapdesignator is schematically moved to the top of the Zone 2 b box toindicate that the B molds is spending its first minute in the 2 b.Schematically, the Zone 2 a box and Zone 1 box is hatched as therespective C mold and A mold are undergoing the first minute of thespray operation. Specifically, the C mold is undergoing the first minuteof the cover coat spray by robot 25B, while the A mold is undergoing thefirst minute of the gelcoat spray by robot 25A.

Referring to FIG. 4C POSITION ONE, the C mold, A mold, and the B moldremain in the same Zones. As the C mold and A mold remain for a thirdminute in the same Zone, the lap designators schematically move to thebottom portion of their respective box to indicate that the molds arespending their third minute in the same Zone. As the B mold remains fora second minute in the same Zone, the B lap designator schematicallymoves to the central portion of its box to indicate that the mold isspending its second minute in the same Zone.

Schematically, the Zone 1 box is shaded as the A mold is undergoing thesecond minute of the gelcoat spray by robot 25A. No operation isperformed on the C mold. Schematically, the Zone 2 b box is hatched asthe B mold is undergoing the first minute of the chop sprayingoperation. That is, robot 25B (FIG. 1) pivots away from the C mold toprovide the first minute of chop coat spray to mold B. Further, if thecover coat spray by robot 25B is completed early, robot 25B canimmediately thereafter pivot to begin the chop coat spray to mold B.

Referring to FIG. 4C POSITION TWO, lap operations for the C mold and Amold are complete. The C mold and A mold, having completed theiroperations are schematically changed to an A mold and a B mold lapdesignation and move into staging area 4 a. As discussed above, the Cmold is designated as an A mold but the finished part must cure throughZone 6 until it is finally removed at Zone 8 (FIG. 4A, POSITION TWO).The A mold becomes a B mold and travels two more laps around the system20. The lap indicator of the B mold within Zone 2 b schematically movesto the bottom of the Zone 2 b box to indicate that it is spending thethird minute at Zone 2 b. Schematically, the Zone 2 b box is shaded asthe B mold is undergoing the second minute of the chop operation (FIG.2).

Referring to FIG. 4C POSITION THREE, lap operations for the B mold iscomplete. The B mold, having completed its operation is schematicallychanged to a C mold lap designation and moves into staging area 4 bwhere a rolling and trimming operation are performed. The B mold is nowa C mold which travels one more lap around the system 20.

Three parts come out of the spray Zones 1, 2 a, and 2 b every threeminutes so one part is pulled every three minutes when thirty molds aretraversing the system 20. Total cycle time is approximately ninetyminutes per molded part using known chemistry.

The foregoing description is exemplary rather than defined by thelimitations within. Many modifications and variations of the presentinvention are possible in light of the above teachings. The preferredembodiments of this invention have been disclosed, however, one ofordinary skill in the art would recognize that certain modificationswould come within the scope of this invention. It is, therefore, to beunderstood that within the scope of the appended claims, the inventionmay be practiced otherwise than as specifically described. For thatreason the following claims should be studied to determine the truescope and content of this invention.

1. A method of molding an article comprising the steps of: (1) defininga closed circuit; (2) transiting a plurality of open molds about theclosed circuit for a plurality of laps; and (3) performing apredetermined series of operations during each of said plurality oflaps, the predetermined series of operations including transiting theplurality of open molds through a spraying operation as a multiple ofsets in which each set includes a reoccurring sequence of open molds inwhich each open mold within each set is on a different lap.
 2. A methodas recited in claim 1, wherein said step (3) comprises a sprayingoperation during each of the laps.
 3. A method as recited in claim 2,wherein said spraying operation occurs within a common spray boothduring each of the laps.
 4. A method as recited in claim 1, wherein theplurality of laps of said step (2) comprises three laps and three openmolds within the set.
 5. A method as recited in claim 1, wherein saidstep (2) comprises transiting a plurality of molds along the closedcircuit in a predetermined sequence.
 6. A method as recited in claim 5,further comprising the step of: ordering the plurality of molds into thespraying operation as a reoccurring sequence of sets of open molds.
 7. Amethod as recited in claim 5, further comprising the step of: orderingthe plurality of molds in a reoccurring sequence dependent upon whichlap each of the plurality of molds has completed.
 8. A method as recitedin claim 1, further comprising the step of: ordering the set with a moldon a first lap following a mold on a final lap.
 9. A method as recitedin claim 8, wherein said ordering step further comprises the step of:following the mold on the first lap with a mold on a second lap.
 10. Amethod as recited in claim 1, further comprising the step of: queuingthe plurality of molds after completion of one of the plurality of lapswithin a queue along the closed circuit.
 11. A method as recited inclaim 10, wherein said queuing step further comprises the step of:curing the plurality of molds while within the queue.
 12. A method asrecited in claim 10, wherein said queuing step further comprises thestep of: segregating the plurality of molds into a first and a secondparallel queue relative to which lap each of the plurality of molds hascompleted.
 13. A method as recited in claim 12, wherein said queuingstep further comprising the steps of: releasing a first mold from thefirst queue; releasing a second mold and a third mold from the secondqueue; and sequencing the third mold after the second mold and thesecond mold after the first mold along the closed circuit.
 14. A methodas recited in claim 1, further comprising the steps of: segregating theplurality of molds into a first queue and a second queue relative towhich lap each of the plurality of molds has completed; transiting themolds within the first queue through a first spraying operation; andtransiting the molds within the second queue through a second sprayingoperation.
 15. A method as recited in claim 14, wherein said firstspraying operation and said second spraying operation are performedsequentially.
 16. A method as recited in claim 14, wherein said firstspraying operation and said second spraying operation are performedsequentially by a single robotic sprayer.
 17. A method of molding anarticle comprising the steps of: (1) defining a closed circuit; (2)ordering a plurality of open molds in a reoccurring sequence dependentupon which lap each of the plurality of molds has completed; (3)transiting the plurality of open molds about the closed circuit for aplurality of laps; and (4) performing a predetermined series ofoperations on each of the plurality of open molds during each of saidplurality of laps, the predetermined series of operations includingtransiting the plurality of open molds through a spraying operation as amultiple of sets in which each set includes a reoccurring sequence ofopen molds in which each open mold within each set is on a differentlap.
 18. A method as recited in claim 17, further comprising the stepof: queuing the plurality of molds prior to said spraying operation. 19.A method as recited in claim 18, wherein said queuing step furthercomprises the step of: segregating the plurality of molds into a firstand a second parallel queue relative to which lap each of the pluralityof molds has completed prior to said spraying operation.
 20. A method asrecited in claim 17, further comprising the step of: segregating theplurality of molds into a first and a second parallel queue relative towhich lap each of the plurality of molds has completed; transiting afirst mold from the first queue through a first spraying operation; andtransiting a second mold from the second queue through a second sprayingoperation.
 21. A method as recited in claim 20, further comprising thesteps of: transiting the first mold from the first spraying operation toa third queue along a common circuit with said first queue; andtransiting the second mold from the second spraying operation to afourth queue along a common circuit with said second queue.
 22. A methodas recited in claim 21, further comprising the steps of: merging thefirst mold from the third queue with the second mold from the fourthqueue into a fifth queue; curing the first mold and the second moldwithin the fifth queue.
 23. A method as recited in claim 21, furthercomprising the steps of: releasing the first mold from the third queue;releasing the second mold and a third mold from the fourth queue;merging the first mold from the third queue with the second mold and thethird mold from the fourth queue into a fifth queue such that the moldswithin the fifth queue are sequenced in a predetermined order; andcuring the molds within the fifth queue.
 24. A method as recited inclaim 23, further comprising the steps of: releasing the first mold,second mold and the third mold from the fifth queue as a set of moldssequenced in said predetermined order.
 25. A method of molding anarticle comprising the steps of: (1) defining a closed circuit; (2)transiting a plurality of open molds about the closed circuit for aplurality of laps; (3) performing a predetermined series of operationsduring each of said plurality of laps, the predetermined series ofoperations including transiting the plurality of open molds through aspraying operation as a multiple of sets in which each set includes areoccurring sequence of open molds in which each open mold within eachset is on a different lap; and (4) removing one of the plurality of openmolds from the closed circuit to perform an off-circuit operation.
 26. Amethod as recited in claim 25, wherein said step (4) comprisestransiting the one of the plurality of open molds along an exit spurwhich extends from the closed circuit.
 27. A method as recited in claim25, wherein the off-circuit operation of said step (4) comprises arepair operation.
 28. A method as recited in claim 25, wherein theoff-circuit operation of said step (4) comprises removing the one of theplurality of molds to a storage area.
 29. A method of molding an articlecomprising the steps of: (1) defining a closed circuit; (2) transiting aplurality of open molds about the closed circuit for a plurality oflaps; (3) performing a predetermined series of operations during each ofsaid plurality of laps, the predetermined series of operations includingtransiting the plurality of open molds through a spraying operation as amultiple of sets in which each set includes a reoccurring sequence ofopen molds in which each open mold within each set is on a differentlap; and (4) transiting a mold along a spur which extends from theclosed circuit to insert an open mold to the plurality of open molds onthe closed circuit.
 30. A method as recited in claim 1, wherein saidstep (3) further comprises ordering each open mold within each set in athird lap, first lap, second lap sequence prior to entering the sprayingoperation.
 31. A method as recited in claim 17, wherein said step (4)further comprises ordering each open mold within each set in a thirdlap, first lap, second lap sequence prior to entering the sprayingoperation.
 32. A method as recited in claim 25, wherein said step (3)further comprises ordering each open mold within each set in a thirdlap, first lap, second lap sequence prior to entering the sprayingoperation.
 33. A method as recited in claim 29, wherein said step (3)further comprises ordering each open mold within each set in a thirdlap, first lap, second lap sequence prior to entering the sprayingoperation.
 34. A method as recited in claim 1, wherein the sprayingoperation of said step (3) further comprises: continually cyclingthrough three positions.
 35. A method as recited in claim 17, whereinthe spraying operation of said step (4) further comprises: continuallycycling through three positions.
 36. A method as recited in claim 25,wherein the spraying operation of said step (4) further comprises:continually cycling through three positions.
 37. A method as recited inclaim 29, wherein the spraying operation of said step (4) furthercomprises: continually cycling through three positions.
 38. A method asrecited in claim 1, further comprising the step of: starting-up andshutting-down the transiting of the plurality of open molds in a stagedmanner.